From bee645788e07eea63055d261d2884ea45c2ba857 Mon Sep 17 00:00:00 2001 From: Waiman Long Date: Tue, 16 Mar 2021 11:31:17 -0400 Subject: [PATCH] locking/ww_mutex: Fix acquire/release imbalance in ww_acquire_init()/ww_acquire_fini() In ww_acquire_init(), mutex_acquire() is gated by CONFIG_DEBUG_LOCK_ALLOC. The dep_map in the ww_acquire_ctx structure is also gated by the same config. However mutex_release() in ww_acquire_fini() is gated by CONFIG_DEBUG_MUTEXES. It is possible to set CONFIG_DEBUG_MUTEXES without setting CONFIG_DEBUG_LOCK_ALLOC though it is an unlikely configuration. That may cause a compilation error as dep_map isn't defined in this case. Fix this potential problem by enclosing mutex_release() inside CONFIG_DEBUG_LOCK_ALLOC. Signed-off-by: Waiman Long Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20210316153119.13802-3-longman@redhat.com --- include/linux/ww_mutex.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/include/linux/ww_mutex.h b/include/linux/ww_mutex.h index 850424e5d030..6ecf2a0220db 100644 --- a/include/linux/ww_mutex.h +++ b/include/linux/ww_mutex.h @@ -173,9 +173,10 @@ static inline void ww_acquire_done(struct ww_acquire_ctx *ctx) */ static inline void ww_acquire_fini(struct ww_acquire_ctx *ctx) { -#ifdef CONFIG_DEBUG_MUTEXES +#ifdef CONFIG_DEBUG_LOCK_ALLOC mutex_release(&ctx->dep_map, _THIS_IP_); - +#endif +#ifdef CONFIG_DEBUG_MUTEXES DEBUG_LOCKS_WARN_ON(ctx->acquired); if (!IS_ENABLED(CONFIG_PROVE_LOCKING)) /*